where At is the sampling interval, taken as 10 msec. The nonlinear
model is then reduced to the following expression:
With the measured aortic flow as the input, a numerical procedure can be
programmed to solve P(ti), C(P) and the aortic pressure
nonlinear and linear model predicted aortic pressure waveforms,
the measured aortic pressure. Dotted line: linear windkessel model; dashed
line: nonlinear pressure-dependent compliance model.
This nonlinear model predicted aortic pressure accurately, as shown
The linear three-element model predicted the measured
aortic pressure with less accuracy, although the
The model-based arterial compliance plotted as a function of
a complete cardiac cycle with a normal blood pressure level
is shown in Fig.
It is clear from this figure that compliance is
both pressure and flow in the early systole and
maintains a value close to its maximum
during this period.